How texture influences the rate of chewing and compression between the teeth

The texture of food plays a crucial role in how we perceive and enjoy it. It also significantly affects the rate of chewing and the amount of compression between the teeth required to break down the food. Understanding these dynamics can provide insights into food design, nutrition, and even dental health. Let’s explore how different textures influence chewing behaviours and the implications for various aspects of eating and food processing.

The science of chewing

Chewing, or mastication, is the process of breaking down food into smaller pieces, making it easier to swallow and digest. The texture of food influences the duration and intensity of chewing, as well as the force exerted by the teeth.

Key factors in chewing:

Food hardness: Harder foods require more force and longer chewing time to break down.
Food elasticity: Elastic foods, such as gummy candies, require more repetitive and forceful chewing.
Food consistency: Thick, viscous foods may require slower, more deliberate chewing to manage the texture and consistency.
Food cohesiveness/adhesiveness: Foods that stick together or to the teeth, like peanut butter, may prolong the chewing process.

Texture and chewing rate

Different textures necessitate different chewing rates. Here's how various textures influence the chewing rate:

Crunchy and hard foods – e.g. Carrots, nuts, apples

Chewing rate: Slow and forceful. These foods require significant force to break down, leading to slower, more deliberate chewing to avoid damage to the teeth and gums.
Implications: These foods provide good exercise for the jaw muscles and can help maintain dental health by stimulating saliva production.

Soft and tender foods – e.g. Ripe fruits, cooked vegetables, tender meats

Chewing rate: Fast and light. These foods are easily broken down, requiring less force and fewer chewing cycles.
Implications: These foods are generally easier to eat and are suitable for individuals with dental issues or those who have difficulty chewing.

Chewy foods – e.g. Steak, dried fruits, gummy candies

Chewing rate: Moderate to slow and repetitive. Chewy foods require sustained effort to break down, often involving repetitive chewing motions.
Implications: These foods can be satisfying to chew but may be challenging for individuals with weak jaw muscles or dental problems.

Creamy and viscous foods – e.g. Yogurt, pudding, mashed potatoes

Chewing rate: Minimal to moderate. These foods require minimal chewing, as they are smooth and easy to compress.
Implications: These foods are ideal for individuals with chewing difficulties or those recovering from dental surgery.

According to Malcolm Bourne (editor of Food Texture and Viscosity: Concept and measurement), the rate of compression between the teeth varies over a wide range and is affected by several factors. The first few chews on a piece of food are frequently slower than the regular chewing rate and that tough foods are masticated more slowly than tender foods.

How widely the jaw is opened affects the compression speed. Some people make short strokes of the jaws whereas others make longer strokes. People who make long strokes will have a higher compression rate if they use the same number of chews per minute because the average compression speed is the product of the number of chews per minute by twice the distance between the teeth at the point of maximum opening.

The mandible articulates is approximately the arc of a circle around the temporomandibular joint. The teeth that are closer to this joint move a smaller distance than the teeth that are farther from the joint. The incisors are the farthest from the joint and move at about twice the speed of the molars. Even among the molars the first molar moves at a faster rate than the third molar because of its greater distance from the temporomandibular joint.

The rate of movement of the jaw follows approximately a sine curve. The actual rate of compression will vary continuously throughout each masticatory stroke, reaching a maximum speed at approximately mid-stroke and falling to zero at the end of the stroke.

If we assume 60 chews per minute as the average chewing rate, and an average stroke length of 10mm, then the average compression rate is 20mm/s but as discussed above, there will be substantial variations from this ‘average’ figure.

The role of compression between the teeth

Compression between the teeth is the force applied to break down food during chewing. Different textures require varying levels of compression:

High compression foods

Examples: Raw vegetables, tough meats.
Force required: High. These foods need significant force to be adequately broken down.
Benefits: High compression can help strengthen teeth and jaw muscles but may cause wear over time if consumed excessively.

Low compression foods

Examples: Soft fruits, cooked grains.
Force required: Low. These foods are easily compressed and require minimal effort.
Benefits: These foods are gentle on the teeth and gums, making them suitable for all age groups, especially children and the elderly.

In general, according to Bourne, the maximum force exerted between the teeth is 15kg between the incisors, 30kg between the cuspids, and 50-80kg between the molars. This range in readings is undoubtedly due to the leveraging effect – the molars are much closer to the fulcrum of the mandible than are the incisors.

Practical implications for food processing and nutrition

Food processing

Understanding the relationship between texture, chewing rate, and compression helps food manufacturers design products that meet consumer preferences and dietary needs. For example:

Elderly nutrition: Soft and tender foods are processed to be easier to chew and digest, addressing common dental issues in older adults.
Children’s snacks: Crunchy yet not too hard snacks are developed to be safe and enjoyable for children.

Dietary choices

Weight management: Foods that require more chewing, such as raw vegetables and lean meats, can increase satiety and help control weight by slowing down the eating process.
Digestive health: Chewing thoroughly improves digestion, as saliva contains enzymes that start the breakdown of food components.

Conclusion

The texture of food significantly influences how we chew and the amount of compression needed between our teeth. By understanding these dynamics, we can make informed decisions about food processing, product development, and dietary choices. Whether it's designing food for specific age groups or managing health through diet, the relationship between texture, chewing, and compression is a key consideration.

For further reading and detailed methodologies, consider exploring resources such as:

These platforms offer in-depth explanations and practical tips for understanding and working with food textures.

Topics: Food Food texture Sensory